In the production of continuous belting, for instance for the manufacture of conveyor belts, it is standard to laminate together the various layers of the belt, typically of outer layers of elastomer sandwiching a core layer of reinforcement as described in U.S. Pat. No. 4,386,014 and then to hot press this laminate together in a continuous press. Such a continuous press can have upper and lower press parts as described in U.S. Pat. No. 4,946,541 through which endless steel liner belts move, or can have heated rollers between which the belt is squeezed.
Clearly it is essential that the press exert a uniform pressure over the entire belt surface in order to avoid squeezing the belt too thin in some locations and leaving it too thick in others. This is not a problem if the belt has a width measured transversely to its normal transport direction through the press that is roughly equal to the press width measured in the same direction.
When, however, a narrower belt is to be pressed, it is normally necessary to press several such belts at the same time. This has the disadvantage that, if the belts abut laterally, they can become laterally fused together, and, if they are spaced somewhat, the edges are subjected to excessive pressure which leaves these edges too thin.
Alternately it is possible to make a single wide belt and subsequently slit it longitudinally to subdivide it transversely into two or more narrower belts. This leaves the reinforcement exposed at the belt edges and is generally expensive and unsatisfactory.